Many packaging applications use resealable containers to store various types of articles and materials. These packages may be used to store and ship food products, non-food consumer goods, medical supplies, waste materials, and many other articles.
Resealable packages are convenient in that they can be closed and resealed after the initial opening to preserve the enclosed contents. The need to locate a storage container for the unused portion of the products in the package is thus avoided. As such, providing products in resealable packages appreciably enhances the marketability of those products.
The resealable closure mechanism is often produced as a separate item from the package and is attached to and made integral with the package at a later point in the manufacturing process by a heat and pressure sealing process. Each separate closure profile includes a base strip and an interlocking member.
One closure profile may have a rib or male member and the other, a mating groove or female member. The male or female member extends from the front face of the base strip. The rib and groove form a pressure-fastenable and releasable closure mechanism. The back side or sometimes an extended portion of the front face of the base strip, is sealed to the package film so that the closure mechanism is disposed between the package walls adjacent to the openable side of the package.
Typically, the base strip and interlocking closure member are extruded in a single extrusion. One disadvantage of this process is that the interlocking closure member and the base strip have to be the same material. Another disadvantage is that different package uses require different base strip designs. When the closure member is extruded with the base stripe the closure member must also be redesigned.